Fingerprint · 2020. 5. 2. · National Police Cadet Corps Activity Time Developing Latent...

Fingerprint

National Police Cadet Corps

Crime Scene Investigation Unit• Well done on completing the first step of becoming an Assistant Investigation

Officer (AIO). Now that you have gone through the Crime Scene

Investigation Introduction, you will proceed to learn more about the

importance of establishing & developing fingerprints found in a crime scene.

• With the knowledge, you will then be tasked to assist the Chief Investigation

Officer (CIO) in several cases which involves some fingerprint dusting

activities.



Learning Objective Learning Outcome

Create awareness on the importance

of establishing & developing

fingerprints found in a crime scene

To manage self-expectations (in a task

that requires patience and

meticulousness) and actively

contribute to a team goal using

collaboration skills.

Purpose of Search for Fingerprints

• Fingerprints found in a crime scene can help to identify possible suspects of

a crime

• Crucial for police officers to preserve fingerprints to aid in solving a crime

• Fingerprints can also be used to convict a suspect in the court of law


Types of Fingerprints



IMPRESSION

Print deposited in a material that retains

the shape of the ridge detail

VISIBLE

Print that can be plainly seen

(made visible by contaminants e.g. oil, grease, blood,

etc)

LATENT

Print that cannot be seen with the

naked eye


• Impression Fingerprints

• Impression is made on soft surfaces like cheese or plastic explosives

• Visible Fingerprints

• Prints left on objects after skin coming into contact with stains

• Rare to find unless the crime was particularly violent or gory

• Latent Fingerprints

• Fingers have friction ridges used to grip surfaces

• Friction ridges are covered with sweat and oils secreted by the skin

• These sweat & oils will be transferred to surfaces they come in contact with, as an invisible

pattern of fingerprint



Where can Fingerprints be Found?

• Fingerprints of an individual can be found on any objects, that the individual

has been in contact with

• Any objects found in a crime scene can be a potential source of evidence

• Tampered fingerprints cannot be used by police officers as evidence thus it

is important not to tamper with the objects found in a crime scene



SURFACES- window

PROPERTIESRECOVERED

TOOLS LEFT BEHIND

GLOVES

CIGARETTEBUTTS

SURFACES- door

SURFACES- vehicle


http://www.dragoart.com/tuts/pics/9/2556/11086/how-to-draw-a-cartoon-car-step-7.jpg

http://www.dragoart.com/tuts/pics/9/2556/11086/how-to-draw-a-cartoon-car-step-7.jpg



NON-POROUS SURFACES

• Not permeable to water, air, or other fluids

• Print found on such surface is very fragile

• Glass, metal, plastics

POROUS SURFACES

• Permeable to water, air, or other fluids

• Print are absorbed into the material

• Paper, cardboard, raw wood

QUIZ TIME!


Name the 3 types of fingerprints that can be found.

• Impression

• Visible

• Latent


Quiz Time

Fingerprint dusting powder can only be used on which type of fingerprints?

• Latent prints


Quiz Time

Which type of surface (porous or non-porous) would you find fingerprints that

are fragile?

• Non-Porous surface


Quiz Time

A fingerprint of Ali was found in a crime scene. The police officer ,Bala, found a

match in the fingerprint database with Ali’s fingerprint. He concluded that Ali

was the culprit. Is Bala right?

• No, solely fingerprints cannot be used to incriminate a person. It can only be

used for substantiation. More evidences must be collected & collated to form

the whole picture of the crime before a conclusion can be made.


Quiz Time


Quiz Time

What is the Learning Objective?

• Create awareness on the importance of establishing & developing

fingerprints found in a crime scene


Quiz Time

What is the Learning Outcome?

• To manage self-expectations(in a task that requires patience &

meticulousness) & actively contribute to a team goal using collaboration

skills


Activity Time

• Now you are ready to assist the Chief Investigation Officer (CIO) in a high

profile case we have on hand. The real action will now begin. Be careful, be

accurate, good luck.


Activity Time

Developing Latent FingerprintsLogistics

•Fiber Brush

•Black Powder

•A sheet of clean white paper

•Scissors

•Gloves

Procedure

•Pour some black powder on the sheet of clean white paper

•Lightly dab brush on black powder1.Only need tips of the brush to be coated

•Stroke the brush on the object for developing fingerprints1.Twirl the brush on the surface of the object for better development of fingerprints

2.Not much contact is needed. Just lightly twirl on the surface of the object

3.Twirl on the surface of the object a few times; going in small circles

4.Applying too much pressure on the surface of the object may smudge the print

•Stroke the brush on the object until fingerprints are seen

•Lightly stroke away any excess powder

•Pour the remaining black powder, on the white paper, back into the jar1.Ensure that the powder to be stored has not been contaminated

Q & A


Congratulations!

• Congratulations! Your important work has contributed to solving the case.

Our colleagues are on their way to arrest the suspects now, and your work

will serve as evidence in court. Good job!

• CIO has recommended you for promotion to Investigation Officer and

Manpower Department will inform you of the decision before the year ends.

There will be another series of tests and interviews before you can be

admitted to the Intermediate CSI training module, where you will learn Police

Photography, DNA Analysis and Bloodstain Pattern Analysis. Till then, all the best!


THANK YOU


Fingerprint · 2020. 5. 2. · National Police Cadet Corps Activity Time Developing Latent...

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